Questions about Mathematica's date and time functions.

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0
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0answers
27 views

Using DatePlus with a list of dates and list of times to add

I have a list of dates such as t2 = {"2016-06-08 05:00:00", "2016-06-08 05:00:00", "2016-06-08 05:00:01"} and a list of offsets (in seconds), such as ...
5
votes
1answer
69 views

How to specify RegularlySampledQ TimeSeries with EndOfMonth date unit MinimumTimeIncrement?

"EndOfMonth" is date unit that can be used with date functions. When specifying a TimeSeries object with date increments you ...
0
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1answer
33 views

Select Time Phase of Dataset with SQLDateTime Objects

I have a Dataset like this: ...
5
votes
1answer
52 views

How to prevent TimeSeries adding TimeObject parameter and TimeZone option to DateObjects?

TimeSeries adds a TimeObject parameter and a TimeZone option to ...
4
votes
1answer
58 views

DateObject with DateFormat displays incorrectly in Dataset

DateObjects with DateFormat option appear to have the first date part truncated when displayed in a ...
6
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2answers
99 views

Speed up AbsoluteTime with string input

I have millions of strings representing dates in the form: "05-Mar-2004 10:15:00". I would like to convert these to absolute times. For example: ...
6
votes
4answers
218 views

Getting AbsoluteTiming to display in hours, minutes, and seconds

I'm doing some extended length calculations and was wondering how I could get AbsoluteTiming to display in hours, minutes, and seconds. I googled and found nothing, ...
4
votes
4answers
417 views

How to convert Dates with format 2016/03/1 to become {2016,3,1}

I have a problem to convert tide data with the form as follows. 2016/03/23,08:00,0.89,* 2016/03/23,09:00,1.41,* 2016/03/23,10:00,1.67,* 2016/03/23,11:00,1.44,* 2016/03/23,12:00,0.82,* 2016/03/23,13:...
3
votes
1answer
63 views

overlap of data

I have two individual Date lists as Date Objects: List 1 = {1 Jan 1991 9 :00 , 3 Jan 1991 11:00 ..etc } List 2 ={ 7 Jan 1991 14:00, 9 Jan 1991 15:00 ..etc} For ...
4
votes
2answers
86 views

How to override DisplayForm of (mixed) time Quantity

What's the best approach to overriding DisplayForm for specific types of Quantity eg time especially w/ mixed units? Current is ...
3
votes
1answer
87 views

How to plot the hour of the sunsets

i have this code: ...
-1
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2answers
65 views

Matching timestamped data

I bet this question is a gimme for most of you guys, but I'm having a bit o' trouble figuring it out. Thanks ahead of time for your input and help. Soooo, I have two datasets where column 1 is a ...
8
votes
2answers
228 views

How to skip weekends in DateListPlot?

How to skip weekends in DateListPlot, ie, drawing 20 something data points for a month and not leaving 2 days gap between weeks? Currently DateListPlot occupied the actual number of days for a month ...
0
votes
1answer
55 views

Combining first 5 columns from CSV file into AbsoluteTime date

Thanks in advance for all your help. I need to import data from a CSV file that looks like : (easier to read in excel) I would like to convert the data into timestamps by creating a Table with 2 ...
3
votes
1answer
48 views

How to get DateListPlot Epilog to display shapes

The following should produced a plot with an orange outlined disc labelled "A" on the dotted line. Epilog produces the dotted line and the text label but is unable ...
2
votes
1answer
105 views

Automatic text-wrapping in labels in `TimelinePlot`

Part-related to this question and part-related to this one, I would like to make use of the new features of TimelinePlot in 10.3, but would like to incorporate some ...
3
votes
0answers
51 views

Possible Bug with DateObject

So my questions is going to be hard to duplicate because I am not sure when or why it happens. I've read here several bugs with DateObject, but none of them ...
5
votes
1answer
47 views

How to modify wrong time zone in a Date object?

How can one modify the wrong time zone in a DateObject, without a conversion? Can one manipulate the TimeZone directly without having the numerical value of the time changing?
0
votes
0answers
44 views
2
votes
1answer
99 views

working hours and negative time [closed]

I have a list of TimeObjects. I want to subtract 5h from each element and if TimeObject < 5h then give a negative hour. My ...
4
votes
1answer
54 views

TimelinePlot - Handling dates prior to Year Zero

Interested in Using TimelinePlot to help me understand/remember important time periods in Earth prehistory and history. Following an a simple example in the Documentation I create a TimelinePlot for ...
5
votes
2answers
100 views

How can DateObject handle calender weeks

I have dates given for a TimeLinePlot. These dates are in {year,week} format. DateObject ...
6
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2answers
151 views

Plot time along the y-axis?

How can I plot times along the Y-axis, (with dates along the X-axis) e.g. ...
2
votes
2answers
44 views

Date Conversion Using Regular Expressions on “Incomplete” Date Formats

I have a list of dates in one of the following formats: "1999/05/12", "1999/05/", "1999//", "****//**/", "" so that a list of such dates might appear as ...
1
vote
1answer
93 views

Why do I get different results for the same input specified using natural language phrasing? [closed]

One of the comments to Stephen Wolfram's blog post on Ada Lovelace, mentioned that WolframAlpha (and verified in Mathematica as well) provided slightly different results for the question of Ada's age ...
1
vote
0answers
34 views

Save a Mathematica notebook evaluated [duplicate]

My notebooks can take some time to evaluate and by quitting Mathematica, I have to reevaluate every definition I've made once I restart Mathematica. Is there a way to tell Mathematica to save the ...
4
votes
2answers
160 views

Finding the positions DateList dates in a range in large data set

There are similar questions to this like list search but this question is focused on finding at subset of dates in DateList format within a range of specified dates ...
5
votes
2answers
157 views

How to convert date string with fractional seconds to DateObject

I have a date/time string from a data file in the form "2014/01/09 07:24:36:001". I would like to convert it to a DateObject. I ...
10
votes
1answer
184 views

DateDifference isn't consistent when giving result in years

This isn't really causing me a problem at the moment, but it's weird. Is this documented anywhere? When I ask for the difference in days and then in years between April 1, 2015 and October 1, 2015 ...
4
votes
1answer
79 views

Working with dates & times - nonatomic expression expected [closed]

Please note that I am new to Mathematica. I am endeavouring to import data from a CSV file with the first column a date and time. The import appears to work fine and returns the results I expect: <...
5
votes
3answers
95 views

How to ignore year in DateListPlot

I just upgraded to Mathematica 10, and I am trying to get the hang of the new TimeSeries data objects, which are preventing my old strategy of overlaying data from ...
4
votes
0answers
38 views

DateObject's DateFormat option has inconsistent result in TimelinePlot LabelingFunction and by direct call

I want to strip time and time zone from dates in the LabelingFunction of a TimelinePlot. I am using the ...
7
votes
1answer
616 views

Why does Mathematica's date for the battle Agincourt differ from the US Navy's?

If I ask Mathematica for the Julian Date for the battle of Agincourt with WolframAlpha["battle of agincourt date"] it reports ...
2
votes
1answer
111 views

DateListPlot show iso week

How can I make DateListPlot show the iso week number? I would like to make a Date plot so that for each dot it will show the iso week date in the x-axis .
13
votes
4answers
370 views

How to evaluate the second argument of Cases only once

I'd like to find a fast but readable way to achieve the following: ...
1
vote
1answer
42 views

Aborting an evaluation automatically after a specified time elapsed

I use the following code to evaluate a series of notebooks: nb1 = NotebookOpen["C:\\Users\\....nb"]; SelectionMove[nb1, All, Notebook] SelectionEvaluate[nb1] ...
3
votes
2answers
115 views

Troubles importing date and time from CSV file

I'm trying to import CSV file with the following format: 20150803 00:00:01.649,1.09675,1.09678 using this code: ...
3
votes
2answers
157 views

Convert DateObject into TimeObject

How to elegantly convert from DateObject to TimeObject? The purpose is to extract time from the DateObject and manipulate only ...
7
votes
1answer
162 views

Determining FinancialData for Countries

How do I determine the FinancialData for Australia. For instance the one for USA follows as: FinancialData["NYSE", "Members"] ...
5
votes
1answer
108 views

DatePlus changes in V10.2, can I return to previous behaviour?

Now in V10.2, DatePlus has changed it behaviour in a undocumented way. Now, DatePlus[n] (with n as ...
2
votes
1answer
107 views

DateListPlot incorrect time zone [closed]

I'm trying to plot energy usage over time using datelistplot but the time zone on the ticks is wrong, data for 7pm shows as 3am The code: ...
4
votes
0answers
93 views

TimelinePlot with Interval in Associations

Bug introduced in 10.2 This is related to a previous question I asked about TimelinePlot and multiple associations (Behavior of TimelinePlot with multiple ...
0
votes
0answers
75 views

How to extract the time t of an interpolated function created by NDSolve? [duplicate]

I'm working with the function NDSolve. I give it the time of integration, the time I want it to evaluate my differential equations. Sometimes, it crashes before the end of its attribuated time ; For ...
2
votes
1answer
44 views

How to adjust the FrameTicks length in DateListPlot?

suppose I have the data for DateListPlot: ...
6
votes
4answers
314 views

How to combine Date and Time objects into DateTime object?

Considering a DateObject d and TimeObject t: ...
1
vote
1answer
186 views

How to make a cumulative time plot?

So I'm working with this data set where there is just one input(a date and time) per line in a .csv file. I've let Mathematica understand the input using "DateStringFormat". The time looks like Year-...
7
votes
2answers
409 views

How much time should one give Mathematica for an integral evaluation?

Sometimes when I do integrals in Mathematica (M), it keeps thinking and thinking and I have no idea what is going on inside M. For how long should one wait or how does one know whether M has not got ...
7
votes
3answers
231 views

Problem About TimelinePlot

Bug introduced in 10.1 and fixed in 10.3 TimeLinePlot was introduced in 10.1 I have some data from wikipedia. ...
2
votes
3answers
465 views

Converting timestamps into a decimal in minutes

I am importing a list of timestamps (hour:minutes:seconds) from a series of text files. I have the list: ...
5
votes
1answer
115 views

Handy dates conversion

I feel like something very basic is missing me, $dateformat = {"Year", "Month", "Day", "Hour"}; date = DateString[$dateformat] DateString["Date"] ...